Back-pressure valve for oil and artesian wells



July1.19z4. 1499,702 A. l.. SMITH Y v BACK PRESSURE VALVE F`OR OIL AND ARTESIAN WELLS Fully l 1924.

A. SMITH BACK PRESSURE VALVE FOR OIL AND AHTESIAN wELLs Filed Oct. 14, 1922 2 sheets-sheen 2' U iii Patented July 1, 1921i. j

narran sr ABNEE L. SMITH, 0F CREEK, TEXAS.

BACK-PRESSURE VALVE FOR OIL AND ABTESIAN Wm Application led October 14, 1922. Serial No.l 594,480.

To all 'whom t may concern:

Be it known that I, Anm L. SMITH,

a citizen of the United States, residing at.

Goose Creek, in the county of Harris and State of Texas, have invented certain new and useful Improvements in Back-Pressure Valves for Oil and Artesian Wells, of which the following is a specification, reference being had to thel accompanying drawings.

This invention relates to improvements in llssick pressure valves for oil and artesian we An im ortant object of the invention is to provi e a device for sealing the lower end of the well screen to prevent the entrance of mud, water, sand and the like thereto which would tend to clog the screen.

A further object of the inventionis to provide means of this character having avalve yielding under internal pressure of the pipe to permit washing of the screen in seating the same and having means whereby the valve may be positively seated to prevent flow when the same is not desired;

A still further object of the invention is to provide a device of this character which is simple in its construction and arrangement, durable in service, readily applied, and a general improvement in the art.

These and other objects I attain by the construction and arrangement shown in the accompanyin drawings wherein for the purpose of il ustration is shown a preferred embodiment of my invention and wherein like reference characters designate like parts throughout.

In the drawings Figure 1 is a side elevation partially inl section showing a back pressure valve constructed in accordance with my invention ap lied to an oil well;

igure 2 is a vertical sectional view through the back pressure valve;

Fi re 3 is a bottom plan view of the packing gland employed at the upper end of the wash pipe rece1ver;

Figure 4 is a plan view of the lower check valve; Figure 5 is a side elevation thereof; Figure 6 is a section through the main valve; and

Figure 7 is a plan view thereof. Referring now more particularly to the drawings, the numeral 10 indicates a well casing, 11 a packer carried by the lower end of the well casing and 12 a screen secured to the lower end of the well casing and adapted to screen from oil or water enteringlghe casing all fine particles which might contained therein. As is well known to those familiar with the art, -the lower ends of these screens are usually provided with threads, as indicated at 12, and to these threads by means of the usual collar 13 applied thereto I attach my back pressure valve which is generally indicated at 14. This back pressure valve comprises a casing 15 threaded interiorly at its-upper end, as at 16, and exteriorly at the same end, as indicated at 17, for coaction vwith the collar 13.4 The lower end of the valve casing is likewise threaded interiorly, as at 18, and exteriorly, as at 19,' for the purpose presently to appear.

Into the upper end of the casing 15 I secure a valve cage 20 embodying a bod portion 21 which is exteriorly screw-three ed for engagement with the threads 16 and which has a bore 22. The lower end of the body portion has a depending tube like extension 23 the bore of which is the same diameter as the bore 22 of the body portion. The walls of this tube like extension have formed therethrough, adjacent the upper end thereof, openings 24 and adjacent the lower ends thereof other openings 25, the

urpose of which will presently appear.

crew-threaded in the enlargement at the upper end of the bore 22 is a valve seat holder 26,'having at its lower interior edge a seat of soft metal such as lead, indicated at 27. Slidably mounted within the bore 22 of the body portion and tubular extension 23 is a piston valve 28. This piston valve has formed upon the upper end thereof sharp edges, indicated at 29, adapted to engage against and `seat in the annular soft metal seat 27 hereinbefore described. The lower end of the tube like extension 23 has secured thereto a valve spring seat 30 against which seats one end of a spring 31, the opposite end of which engages against the lower end of the valve to force the same upwardly into engagement with the seat 27 The piston valve 28 comprises a body portion 32, upon the upper face of which is formed the sharp edge 29 forv engaging the seat 27. This end has formed centrally thereof a slight extension, indicated at 33, and to which is secured a swivel eye 34 with which a wire 35 is engaged for a purpose presently to appear. The lower end of the body portion 32 is provided with a reduced extension 36 and the body portion upon its outer surface has ad step reduction 37. The reduced extension 36 has .seated thereon against the body portion 32 piston valve prior to placing the collar 38 in position, a achng ring 43 is placed about the step re uction- 37 and the collar when placed 1n position, retains t rin in position. Similarly upon the step re uction 39 e ring 44 is placed, and this ring is in turn held 1n position by the retaining member 40. Through the retaining member and the extension 36 a cotter pin 45 is placed, the reduction of the retaining member at 41 ermittin placement of this pin without an er o its coming into contact with the wa s ofthe bore of the tube like extension.

Threaded within the lower end of the valve casing 15 is a check valve seat 46 having a central aperture in which is seated a check valve 47, bein provided about this a erture with a raise ridge or shoulder 48. e check valve seat 46 is of considerable thicknessand the central opening thereof a'ords a guide for the check valve which is provided with relatively long guide vanes 49.. -[Upon its lower face the check valve has a downwardly extending portion 50, the lower end of which comes in contact with a central abutment 51 formed upon a spider 52 having threaded engagement in the lower end of the valve casing ybeneath the seat 46, prior to the disengagement of the guide vanes 49 from the seat 46 so that there is no dauer of this valve being lost from its seat. etween the s ider and the valve a spring 53 extends w ich surrounds the extension 50 of the valve and the abutment 51, the spring normally maintaining the valve in engagement with the shoulder 48 of the seat which tends to embed itself in the soft face carried by the valve and formed of leather or the like, this face being indicated at 54.

The up er end of the body portion 21 ofthe va ve cage hereinbefore described is spaced below the upper end of the casing 15 and the threads thus exposed form a seat for a wash pipe receiver, indicated generally at 55. This wash pipe receiver has a bore 56 adapted to receive the lower end of the wash pipe and has its upper end Meegos externally screw-threaded, as indicated at 57. 'llhc member`58 is a packiner land having at its lower end a thi-cade bore 59 adapted to engage the external screw-threads at the upper .end of the wash pipe receiver, the bore at its upper end being restricted by the inwardly extending shoulder 60 opposing the upper end of the wash pipe and coasting therewith to compress the packing placed therebetween and cause the same to engage against the outer face of the wash pipe. rllhe upper end of the packing gland 58 is frusto-conical in form and if desired may be employed as a seat for a frusto-conical flange of soft metal formed upon the wash pipe, as indicated at 61, to further assist l1n sealin the same. The wash pipe 57 has secure to the lower end thereof, as by means of pin 62, the upper end of the wire 35, for a purpose presently to appear.

lin the use of the device, the wash pipe is seated in the upper end of the wash pipe receiver 55 and pump pressure provided for forcing water therethrough, the pressure being prevented from returning through the screen and casing by the packing gland and frusto-conical seat provided at the upper end of the wash pipe receiver as hereinbefore described. This pressure acting against the piston valve 28, forces the same downwardly until the ports or openings 24 are exposed so that the pressure may pass thereby, any collected water beneath the piston passing out through the openings 25. rll`he pressure within acts against the valve 47, opening the same and the water under pressure passes through the lower end of the casing 15, acting against mud and collected sand in the bottom of the well causing the same to move upwardly at the sides of the casing, permitting the screen and back pressure valve to be seated at the bottom of the well. Accumulated dirt and mud is also washed away from the surface of the screen and caused to come to rest at the top of the sand in which the screen is placed upon release of the pressune. The piston valve and valve 47 are returned to their seats, the soft facing upon the lower valve preventing grains of sand and the like from holding the valve open and the sharp edges of the upper valve permitting the same to shear agalnst anything which ma have become caught in the ports 24 an yreturn toits seat. ln event the elements against which the valve must act to return to its seat arc of such structure that the strength of the spring is insufficient to cause the valve to shear the same when the wash pipe is elevated after the washing is applied, the pull exerted by, the wire 35 before breaking, will cause such shearing action, forcing the piston valve upwardly until the sharp edges thereof are iirmly llld mesme cally closing when the washing pressure isv relieved, again sealing the lower end of the screen. It will furthermore be obvious that the structure hereinbefore set forth is capable of many changes and modications without materially departing from the spirit of my invention and I accordingly do not limit myself thereto except as hereinafter claimed.

I claim 1. In combination with a well screen, a valve structure engaged with the lower end of the well screen includin a valve opening in response to pressure interiorly of the screen, means for automatically reseating said valve when open, said valve including a cage having a bore, the walls of the bore havin o enings therethrough, a valve plston slida ly `fitting the bore and having a seat, said valve being provided with a shearing edge adapted to engage said seat and tohave wiping engagement with the bore of the cage.

2. In a device of the type described, a casing adapted for attachment to the lower end ofV a well screen and provided at its upper end with means for receiving the lower end of a wash pipe, an upwardly seating valve arranged within the casing, a seat for said valve, downward movement of the valve opening communication through the casing to permit passage of water from the wash pipe, yieldable means normally holding the valve against its seat, and means connecting the wash pipe and valve for positively seating the valve.

3. In a device of the type described, a casing adapted for engagement with the lower end of a well screen, a valve cage arranged within the casing and embodying a body portion secured to the walls of the casing and having a bore, said body portion bein provided upon its lower end with a depen ing tube like structure, the bore of which forms a continuation of the bore of the body portion, a piston valve mounted within the bore, openings formed in the upper end of the tube like structure communicating with the bore, a valve seat carried by the body portion at the upper end of the bore and with which the piston valve is adapted to coact, and means normally holding said piston valve in engagement with said seat.

4. In a device of the type described, a casing adapted for engagement 'with the lower end of a well` screen, a valve cage arranged within the casing and embodying a body portion secured to the walls of the casing and having a bore, said` body portion being provided upon its lower end with a deplending `tube like structure, the bore of whic forms a continuation of the bore of 'the body portion, a piston valve mounted within the bore, openings Jformed in the upper end of the tube like structure communieating with the bore, a valve seat carried by the body portion at the upper end of the bore and with which the piston valve is adapted to coact, means normally holding said piston valve in engagement with said seat, vmeans at the upper end of the casing for receiving a wash pipe, and meansvconnecting the wash pipe and valve for positively seating the valve upon elevation of the wash pipe. p

5. In a1! evice of the type described, a casing adapted for engagement with the lower end of a well screen, a valve cage arranged within the casing and embodying a body portion secured to the walls of the casing and having a bore, said body portion bein provided upon its lower end with a de en ing tube like structure, the bore of w ich forms a continuation of the bore of the-body portion, a piston valve mounted within the bore, openings formed in the upper end ofthe tube like structure comvmunicating with the bore, a valve seat carried by the body portion' at the upper end of the bore and with which the piston valve is adapted to coact, means normally holding said piston valve in engagement with said seat, means at the upper end of the casing for receiving a wash pipe, and means connecting the wash pipe and valve for positively seating the valve upon elevation of the wash pipe, including a breakable wire connected at one end to the valve and at the opposite end to the wash pipe.

6. In a device of the type described, a casing adapted for engagement with the lower end of a well screen, a valve cage arranged within the casing and embodying a body portion secured to the walls of the casing and having a bore, said body portion being provided upon its lower end with a depending tube like structure, the bore of which forms a continuation of the bore of the body portion, a piston valve mounted. within the, bore, openings formed in the upper end of the tube like structure communicating with the bore, a valve seat carried by the body portion at the upper end of the bore and with which the piston valve is adapted to coact, and means normally holding said piston valve in engagement with seid seat, said valve being provided upon the upper end thereof with e peripheral shearing edgehuvinw sliding enge ement with the Walls of Ihe bore and tu e like structure.

7. lin a device of the type described, e

casing adapted for engagement with the lower end of a Well screen, a valve cage arranged Within the casing and embodying a body portion secured' to the Wells of the casing and having a bore, Said body portion being provided upon its lower end with e de ending tube like structure the bore of Whic forms a continuation of the bore of meme@ signature.

ABNER L. SMli'llH. 

